Car retarder



Sept l 7, 1929. L; o. GRONDAHL 1,728,562

CAR RETARDER Filed Aug. 1a, 1925 2 sheets-sneer 1 5? 52 ;/I2a l IZ 11a 11 a a W 5 W 28a 51@ 52 25 g5/1T Ra 5' R 30 I3 23 L Z5 9a Z4 ..94 .Q 14 A1 lo 176L if? I, 17 10 Q A .www 27 16;

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' 17 INVENTOR:

E gfwow, BY

L. O. GRONDAHL CAR RETARDER sept. 17, 1929.

Filed Aug. 18, 1925 2 Sheets-Sheet 2 an@ Mgg@ BY I ALE ATTORNEY Patented Seprt. 17, 1929V` UNITEn STATES PATENT ,OFFICE I.

LARs o. GRoNnAnL, or PITTSBURGH, PENNSYLVANIA, AssIeNoR To THE yUNIoN swITcII & SIGNAL COMPANY, F swIssVALE, PENNSYLVANIA, Ay CORPORATION 0F PENNSYLVANIA CAR RETARDEB Application ledAugust ,'18, y1925.'. Serial No. 50,898.`r

My invention relates to car retarders, that is to devices located in the trackway for reducin l the speed of railway cars by co-action with lie wheels or other parts of the cars.

I will describe several forms ot car retarders. embodying my invention, and will then point out the novel features thereof in claims.

In the accompanying drawings, Fig; 1 is l? a View inend elevation oil. one term oit car retarder embodying my invention. Fig. 2 is atop planvicw of part oit the retarderr shown in Fig. 1. Fig. 3 is a View showing a modification of a portion of the retarder shown in Figs 1 andi2.` Fig. 41 is a view similar to Fig. 1 but sl'iowing ltwo brake bars co-operating with each wheel of the car. Fig. 5 is a view showing a moditlcationo'f a portion of the apparatus shown in Fig. alf.

ySimilar reference characters lrelier to simi-y lar parts in each of the several views.

Referring rst to Figs, 1 and 2, the reference characters R and Rat designate'the track rails of the railway, which rails are supported on ties 5 inv such manner that the weight of a car will causey these ties to move downwardly toan appreciable extent.k Located on the rails R audflft area pair oi' carr wheels Vand la connected by an axle 29.

Pivotally mounted at the point 10 in a block 27 is a leverrA having one arm 9 eX- tended into a foot which located under the track rail R and the ties 5, and a second arm 30 extending upwardly and terminating in or attached to a brake bar 8 located :close proximity'to the outer side of they car wheely W. yrllhislever is so shaped and proportioned that when` the ties 5 are moved downwardly by the weight ot the cary the l0 brake bar`8 moved into engagement with the side ol.l the wheel. lV with considerable force unless this movement is restraii'xed. Themovement of the lever A into braking position is normally restrained by a latch 1,1

/lwhich rispivot-ally mounted at the point'r 28r and is normally in position to engagea dog 31 formed on the arm 30 of the' lever A. VVhen this latcliis yin engagement with 'the dog 31", counter cloclnvise movement of' the 5,0le'v'er A about its pivotal point 10 is pre vented and so the brake bar y8 does not engage with the car wheel V, Electromagnetic means are provided for at times swinging the latch 11 out of its restraining p0-k sition, this means as here shown being a plunger 32y connected ,with the latch kkand, winding 12 surrounding the plunger When the winding 12 is energized `the plunger 32 is driven upwardly therein and s0y the latch 11 is lifted out of position for engagement with the dog 31, The center of gravity of the lever A may be tor the right of rthe pivotal point 10 so `thatwhen the track rails are unoccupied this lever will swing in clockwise directionto'its normal position wherein the latch 11 will drop into engagement with the dog31. yIf desired however y,otherbiasing means maybe provided for causing the lever A to return yto its normal position whenthe rails are unoccupied. y f f Associated with the lefthand track rail R is a second lever A which is similar in all respects to the lever A but is so located that its associated brake barSa co-operates with the outerffaee ol the cark wheel lV. yThe lever Af isplvotallymounted at 10a in a block 27, and is provided with a latch 11 which normally restrains the ymovement ofr the lever A into braking position. The lat-ch 11a is pivotally mounted at 'point 28 andr is provided with ay plunger 32:L controlled by a solenoid 12l arranged when energized to swing the `latch out of restrainingy position.

The solenoids12 and 12a may be controlled arecontrolledby `a normally open manually operable contact 13, and by a norn'iallyclosed contact 14 ,which is opened" by the downward movement 'of one 'of the ties 5 when a cary passes theretarder. Vhen the contact 13 is in "any suitable maimer.y yAs here shown they closed,it completes a circuit which passes i from battery 33, through contact 13, winding i of arelay 15, contact 14 and solenoids 12 and 1.2n in multiple to battery 33. The solenoids 11 and 111pout of restraining positions, so that a car passing through the retarder will have its speed reduced by the engagement of '12 and 12n then functionto raise the latches ring effort.

the brake bars 8 and 8 with the wheels W and l, respectively. The `energization of relay 15 will cause contact 16 of this relay to close and this Contact will close a. branch around the manually operable Contact 13, so that contact 13 may be released without causing Cle-energization of the solenoids 12 and 12a. rllhese solenoids will then remain energized until thn contact 14 is opened by a car passing throL g i the retarder.

ln order to adjustably limit the braking action of the brake bars 8 and 8, and also to release the retarder if a car comes to rest with the brake bars in engagement with the wheels, the two levers and A are provided with arins 17 and 17 respectively, and means are provided for limiting the downward movements of these arms as well as for raising these arms when it is necessary to release the retarder. This means as here shown comprises a block 23 the ends of which are bifurcated to receive the ends of the arms 1T and 1TfL respectively, the bifurcated ends of block 23 being pivotally attached to these arms by studs 24E .and 24a. rl`he block 23 is provided with a threaded hole to receive a screw 18 which is attached to a gear "i9 co-acting with a worm 25 which is mounted on a shaft 7 and is driven by an electric motor M. rl`his motor may be controlled from a distant point such for example as the cabin wherein the manually operable contact 13 is usually located. The lower end of the screw 18 terminates in a plunger 3 which moves in a cup-shaped guide 21, and a coiled spring .il is interposed between this plunger and the licor of the guide. The amount of compression of this spring is determined by the distance between block 23 and the plunger 3. 1When bars 8 and 8a are in cont-act with the car wheels, the block 23 will occupy a definite position assuming that block 23 is relatively low on the screw 18, then when this block occupies its definite position due to the brake bars being in Contact with the car wheels, the spring is under a relatively light compression so that a relativ 1v large proportion of the car weight is elective at the brake bars to produce brak- Conversely, assuming that the block 23 is relatively highon the screw 18, then when the block 23 is in the same definite position the spring is under a relatively heavy compression and a relatively small proportion of the car weight is effective at the brake bars to produce braking effort. 1t is of course understood that the force required to compress a spring increases substantially in proportion to increase yin the amount of compression ofthe spring.

It' will be seen that if a car comes to rest in the retarder while the levers A and A are in braking positions, these levers may be released by raising the arms l17 and 17a by suitable operation of the motor M.

Then the operator desires to retard a car he will first cause operation of the motor M to place the block 23 in such position on the screw 18 as to accomplish the desired braking effort, and he will then close contact 13 to release these levers. After the car passes through the retarder the latches 11 and 11a will be automatically released by the contact lll, and the levers A and' A will automatically return to their non-breaking positions wherein they will be locked.

As shown in Fig. 2 the brake bar 8a extends longitudinally along the track for a considerable distance, and is provided with two levers A, A', located at spaced longitudinal points on the bar 8, A larger number of levers A may be provided for the arm 8a if desired.

Referring now to Fig. 3 the apparatus in the form here shown is the same as that shown in Figs. 1 and 2 except that the brake bar 8 is separate from the levers A and is spaced therefrom by springs 20, these springs co-acting with a longitudinal arm 38 which is attached to or integral with the levers A.

As shown in Fig. 1 there is but one brake bar co-acting with each wheel l and Wa. In some instances it may be desirable to provide two brake bars for each wheel co-acting respectively with the opposite faces 0f such wheel. Referring now to Fig. d, the apparatus shown in this view is similar to that shown in Fig. 1 in so far as levers A and A are concerned but the retarder is provided with two additional levers C and C. Lever C is pivotally mounted at point 34' in a block 35 and is provided with an arm 36 located.

under the track rail R and with an upwardly extending arm 37 which terminates in a brake bar 8"' arranged to co-act with the inner surface ofthe car wheel W. lfVhen thc ties 5 move downwardly in response to the 3a so that brake bar 8c engages the wheel l with considerable pressure. The wheel WV is thus clamped between the two brake bars 8 and 8C, so that the forces exerted on this wheel by the retarder are substantially equal and opposite, with the result that the strain on the axle 29 is substantially Zero. The structure and operation of the lever C will be understood without further explanation, the brake bar associated with this lever being designated 8d. The levers A and A shown in Fig. 4 may be provided with restraining latches or with adjustable limiting means, or with both as shown in Fig. 1.

Referring now to Fig. 5, the apparatus shown in this view is similar to that shown in Fig. l except that the lever C is provided with a third arm` 39 which projects downwardly beneath arm 17 and is provided with a threaded hole to receive the screw car, a brake bar moved into braking position by said member when depressed, means for preventing movement of said brake bar in response to the weight of a car, and means for adjustably limiting the braking pressure exerted by said bar when said preventing means is not effective.

14. A car retarder comprising a brake bar, means operated by the weight of a car for moving said bar into engagement with a wheel of a car, meanst'or preventing movement of said brake bar in response to the weight ot a car, and means for adjustably limiting the braking pressure exerted by said bar when said preventing means is not effective.

l5. A car retarder comprising a lever having one arm located under a track rail for depression by the weight oit a car and another arm located in position for engagement with a side of a. car wheel and a third arm, and means cO-acting with said third arm for limiting the braking pressure exerted by said lever in response to the Weight of a car.

16. A car retarder comprising a brake bar, means operated by the weight of a car Jfor moving .said bar into engagement with a wheel of a car, and means for releasing said retarder if a car stops therein.

17. A car retarder comprising a lever having one arm located under a track rail for depression by the weight of a car and another arm located in position for engagement with a side of a car wheel and a third arm, and means co-acting with said third arm for releasing said second arm from the wheel if a car stops in the retarder.

18. A car retarder comprising a brake bar, means operated by the weight of a car for moving said bar into engagement with a wheel of a car, and a screw jack tor moving said bar out of engagement with the wheel if a car stops in the retarder.

19. A car retarder comprising a brake bar, means operated by the weight of a car for moving said bar into engagement with a wheel of a car, anda screw jack for limiting the braking pressure exerted by said bar and for releasing the bar from the car wheel if a car stops in the retarder.

20. A car retarder comprising a brake bar, means operated by the weight ot a car for moving said bar into engagement with a wheel of a car, a screw jack for moving said bar out of engagement with a car wheel, and an electric motor for operating said jack.

21. A car retarder comprising a brake bar,

means operated by the weight or" a car for moving said bar into engagement with a wheel of a car, a latch for restraining such qmovement of said bar, a magnet for releasing said latch, a screw device for limiting the braking pressure exerted by said bar in response to the weight oi a car, a motor for operating said screw device, and means tor controlling said magnet and saidmotor from a distant point.

22. A car retarder comprising a brake bar, means operated by the weight ot a car for moving said bar into engagement with a wheel of a car, a latch for restraining such movement of said bar, electromagnetic means for releasing said latch, and a screw device for adjustably limiting the braking pressure exerted by said bar when the bar is released. y 23. A car retarder comprising a brake bar, means operated by the weight of a car for moving said bar into engagement with a wheel of a car, and a screw device for adjustably limiting the pressure exerted on the car wheel by said bar. l

24. A car retarder comprising a brake bar, means operated by the weight of a car :tor moving said bar into enga-gement with a wheel of a car, and means controlled from a distant point tor adjustably limiting the pressure exert-ed on the car wheel by said bar.

25. A car retarder comprising a lever having yone arm located under a track rail for depression by the weight of a car and another arm located in position for engagement with a side of a car wheel when the first arm is depressed, and a third arm; a second lever having one arm located under the track rail for depression by theweight ot' a car, and a second arm located in position for engagement with the other Aside of the car wheel when the irst arm is depressed, and a third arm; and means co-acting with said third arms for adjustably limiting the pressures exerted on the car wheel by the second arms of said levers.

Q6. A car retarder comprising a lever having one armlocated under a track rail for depression by the weight ot a car and another arm located in position for engagement with a side of 'a car wheel, when the first arm ris depressed, and a third arm; a second lever having one arm located under the track rail for depression by t-he weight of a car, and a second arm located in position for engagement with the other side of the car wheel when the iirst arm is depressed, and a third arm; a screw device co-acting with said third arms for adjust-ably limiting the pressures exerted on the car wheel b-y the second arms of said levers, and a motor for operating said screw de.- vice.

27. A car retarder comprising a brake bar, means operated by the weight of a car for moving said bar into engagement with a wheel ot a car, a second brake bar, and means operated by the weight of the car for moving said second. bar into engagement with the other side of the car wheel.

28. A car retarder comprising a brake bar, means operated by the weight of acar for moving said bar into engagement with a wheel of a car, a second brake bar, means operated by the weight of the car for moving said second bar into engagement with the other side oi' the car wheel, and means for adjustably limiting the pressure eX- erted on they wheel by at least one of said bars.

29.,A car retarder comprising a brake bar, means operated by the weight of a car 'for moving said bar into engagement with a wheel of a car, a second brake bar, means operated by the weight of the car for moving said second bar into engagement with the other side of the car wheel, andmeans for adjustably limiting the pressures exerted on the wheel by said bars.

30. A car retarder comprising a braking member constantly in position to be operated by the weight of a car, and means for restraining operation of said member in response to the weight of a car.

31. A car retarder comprising a brake bar movable into engagement with a car wheel by the weight of a car, and means including a spring and a screw device for adjustably limiting the pressure exerted on the wheel by said bar.

bar, means operated by the weight of a car for moving said bar into engagement with a wheel of a car, a secon-d brake bar, means operated by the weight of the car for moving said second bar into engagement with the other side of the car wheel, a spring for limiting the pressures exerted by said bars on a car Wheel, and means forvarying the effect of said spring on said bars.

In witness whereof I aix my signature.

LARS O. GRONDAHL.

32. A car retarder comprising a brake bar movable into engagement with a car wheel by the weight of a car, a spring for limiting the pressure of said bar on the car wheel, and means for varying the effect of said spring on said bar.

33. A car retarder comprising a brake bar movable into engagement with a car wheel by the Weight of a car, a spring for limiting the pressure of said bar on the car wheel, and remotely controlled means for varying the compression of said spring.

34. A car retarder comprising a lever having oneV arm located under a track rail for depression by the weight of a car and another arm located in position for engagement with a side of a car wheel and a third arm, a spring coacting with said third arm for limiting the pressure exerted on the car wheel by said second arm, and means for varying the effect of said spring on said third arm.

35. A car retarder comprising al lever having one arm located under a track rail for depression by the Weight of a car and another arm located in position for engagement with a side of a car wheel when the first arm is depressed, and a third arm; a second lever having one arm located under the track rail for depression by the weight of a car, and a second arm located in position for engagement with the other side of the car wheel when the first arm is depressed, and a third arm; a spring interposed between said third arms, and means for varying the force exerted on said third arms by said spring.

36. A car retarder comprising a brake 

